Building automation concepts have been known for some time. However, in general, these concepts have been limited to large industrial settings or to custom-designed systems for luxury homes because of the prohibitive cost associated with conventional automation systems. In addition, automation systems generally have been placed in new structures because of the substantial wiring necessary to implement these systems. Retrofitting automation systems in existing structures has been unpopular because, in general, the procedure is invasive and may require destruction of interior surfaces, substantial rewiring, significant expense, and inconvenience to the homeowner or tenant.